Where to find clients?

Hello again friends, I have the following question, I want to offer a service, I do not have advertising or it is something that I can advertise, it is something similar to what they have already done to sell premium shopify themes. But I do not know where to offer it, try to enter related telegram channels and if I sold a pair but it was removed by spam. On Facebook my posts do not usually go beyond the admins, and when they do they do not have much attention

following

Facebook ads is good

Make a Landing Page
Do your keyword research
Buy some Google ads coupon
Buy some Bing Ads Coupon
Use the keywords to set up ads to your landing page and optimize stuff.